Lock mounting pad
BACKGROUND OF THE INVENTION 
     This invention relates to a structure for mounting a locking mechanism to a door. In particular, the invention relates to the structure for locking a mounting pad to a door stile the locking pad holding a lock cylinder therein, the lock cylinder activating appropriate latching mechanicals located within a door stile. 
     Known to the art are locking pads, which hold a lock cylinder, which are attached to the door stile by two screws which penetrate a thickness of the door stile from a direction opposite the mounting pad, the screws engaging the mounting pad at appropriate threaded connections on the mounting pad inside the door stile. The screws, when rotated, draw the mounting pad up against the door. By using this method, the screw heads of the two screws are visible from an opposite side of the door from the locking pad. A disadvantage in the prior art application is that the screw heads are accessible to unauthorized persons, who can remove the mounting pad and/or tamper with it. 
     The present invention alleviates these problems by locating the mounting screws in an orientation which is neither visible nor accessible once the mounting pad and additional door structures are installed. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a structure and method for installing a lock mounting pad to a door wherein the mounting fasteners are neither visible nor accessible once the door is assembled. The lock mounting pad structure can be utilized in a variety of types of doors, including hollow frame doors, wooden doors, doors with glass interiors, or solid doors, or any door of appropriate construction. 
     It is an object of the present invention to provide: 
     a mounting pad for holding a lock cylinder therein, easily assembled, and having a sturdy construction; 
     a mounting pad assembly having a minimum of parts to simplify assembly; 
     a mounting pad assembly requiring minimum machining or forming of the door or door stile for accepting the mounting pad; 
     a mounting pad that once installed, eliminates visible fasteners which hold the mounting pad to the door; 
     a mounting pad which prevents tampering with the locking mechanism; 
     a mounting pad which reduces the precision requirement of the prior art for aligning parts such as the lock activating mechanism or cam of the lock cylinder with the locking mechanicals of the door, and the attachment screws with threaded mounting pad screw holes; and 
     a locking mechanism including the lock cylinder, the mounting pad, and fasteners which can be preassembled remote from the door and quickly and efficiently installed to the door, saving installation and maintenance time when installing, repairing, or changing out the locks for security reasons. 
     The objects are inventively achieved in that a locking mechanism is provided which: 
     provides a sturdy mounting pad having a plurality of rugged bosses which receive set screws to engage the mounting pad to the door, and a lock collar to mount the lock cylinder therein; 
     provides a flange and lock ring arrangement to install the lock cylinder inside the mounting pad; 
     provides that the set screws are located interior of the door and accessed by a tool which penetrates the door to activate the set screws to engage an inside surface of the door, the set screws thereafter being not visible or accessible from positions exterior to the door; 
     provides a set screw arrangement which engages a surface, rather than a set screw arrangement which engages threaded holes, thus eliminating a degree of precision in mounting the mounting pad to the door while simultaneously engaging the lock cylinder cam to particular locking mechanicals in the door, eliminating the requirement that the screws be manually aligned, through a thickness of the door, to mate with corresponding screw holes; 
     provides a method of installing a lock mounting pad wherein the set screws can be accessed through openings in the door, the openings being required and designed for other purposes such as the openings required for installation of a panic exist device or panic bar, thus by utilizing such openings machining of the door is reduced as, separate designated access openings for the set screws would be eliminated; 
     provides a method of installing a locking mechanism wherein tampering of the locking mechanism is reduced because the set screws for mounting the lock mounting pad are not accessible, the opening used for activating the set screws being covered by an internal panel or structure of the door or a panic exit device; 
     provides a locking mechanism which comprises only three assembled parts: the lock cylinder, the lock ring, and the mounting pad assembly with set screws preinstalled, the assembly being preassembled remote from the door and locking mechanism thus being changeable out quickly and efficiently. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a door having a locking mechanism installed thereon; 
     FIG. 2 is a fragmentary sectional view, viewed generally along line II--II of FIG. 1, showing the locking assembly fit up to the door but not yet engaged; 
     FIG. 3 is a fragmentary sectional view also viewed generally along line II--II of FIG. 1, showing the locking mechanism engaged to the door including a tool inserted for engagement; 
     FIG. 4 is a partial sectional view, viewed generally along line IV--IV of FIG. 3; and 
     FIG. 5 is an exploded perspective view of the locking mechanism. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a door generally at 10 comprising a rectangular frame 20 having an interior panel 30. The frame can be of a variety of constructions, in the preferred embodiment it is a hollow type frame. The panel 30 can also be a variety of constructions, such as a glass panel having perimeter framing 32. The present invention is equally applicable to composite doors, or solid doors. All metal frame doors such as aluminum or steel, or wooden doors or any suitable material doors are encompassed by the invention. 
     The frame 20 comprises a door stile 34 on one side. The door stile 34 is generally located adjacent to a swinging edge 34a of the door opposite a hinged edge 35. The door stile 34 holds a locking mechanism 40 which can extend outwardly of the door, to lock the door to a door frame through various openings depending on the locking mechanicals. A side opening 44a is shown wherein a latch 40d, shown in FIG. 7 could protrude outwardly to engage a doorway frame 40e, shown in FIG. 7. An alternate location for an opening is a top opening 44b wherein the locking mechanism 40 would communicate with a dead bolt type mechanism 40b shown in FIG. 6 to extend a top dead bolt outwardly of top opening 44b to engage the doorway frame. A bottom opening 44c is shown dashed and could, similarly to top opening 44b, be used in conjunction with a bottom dead bolt 40c shown in FIG. 6 to engage the doorway frame. All three openings 44a, 44b, 44 c could be used alone or in select combination with each other. 
     FIG. 2 shows a mounting pad 60 pressed flush against a receiving surface 61 of a receiving wall 62 of the door stile 34. The receiving surface 61 could be oriented on either side of the door 10, interior or exterior, depending on the purpose of the application. Normally, the receiving surface 61 is on an exterior side of the door 10 for the purpose of locking the door from outside of a dwelling to prevent subsequent entrance by unauthorized persons. The receiving wall 62 of the door stile 34 has a plurality of openings therein to receive the mounting pad 60. A circular lock hole 63 is shown in FIG. 4 and will be described below. A first boss opening 64a and a second boss opening 64b are arranged above and below the lock hole 63, and are offset on either side of a vertical centerline 65 of the lock hole 63 (shown in FIG. 4). 
     The mounting pad has formed thereon anchor portions such as a first boss 66 and a second boss 68. The two bosses 66, 68 protrude from a back side 67 of the mounting pad 60. The bosses 66, 68 are of a slightly tapered cylindrical shape, first boss 66 having a first bore 66a therethrough with an axis inclined to an engagement surface 69 of the door stile 34, second boss 68 having a second bore 68a having an axis also inclined to the engagement surface 69 of the door stile 34. The door stile 34 is shown having framing lips 70a, 70b for holding structure such as the perimeter framing 32 which holds the inside panel 30. 
     The mounting pad 60 as shown in FIG. 2 is shown without a lock cylinder 100 (shown and described with regards to FIG. 5) installed, or an inside lock collar 110 (also shown and described with regards to FIG. 5), for clarity. Normally the lock cylinder would be installed into the mounting pad 60 before the mounting pad 60 is mounted to the door 10. 
     FIG. 3 shows how the mounting pad 60 is secured to the door stile 34. The first boss 66 holds a first set screw 76 threadingly inside the first bore 66a. THe second boss 68 holds a second set screw 78 threadingly inside second bore 68a. Both the first bore 66a and the second bore 68a are inclined away from the engagement surface 69 toward a stile panel surface 79 provided on a stile interior side wall 80. A first tool access hole 79a provides a passage through stile panel surface 79 to communicate with the first set screw 76. A second tool access hole 79b shown in FIG. 3 and FIG. 4, aligned coaxially with the second set screw 78, provides a second passage through the stile panel surface 79. An engagement tool 82, in the preferred embodiment an Allen wrench, is designed to engage the set screws 76, 78 to impart rotation to the set screws. The engagement tool 82 communicates to the set screws 76, 78 through the tool access openings 79a, 79b. Alternatively, the tool access holes 79a, 79b can be a single opening 41 or a plurality of openings which are utilized for other purposes such as mounting a panic exit device 42, particularly to communicate an operating lever 43 of a panic exit device into the door stile to engage a door latching mechanism 40a, shown in FIG. 6, 7. Such a single opening or lever opening 41, is disclosed in FIG. 1 of U.S. Pat. No. 4,839,988 comprising a generally rectangular composite shape. Therefore, it is a novel feature of this invention that machining of the door stile, such as cutting additional tool access holes into the door stile, is eliminated. A door latching mechanism residing inside a door stile and a panic exit device with a lever communicating through a lever opening in the door stile to the latching mechanism is also disclosed in U.S. Pat. No. 4,839,988. 
     It is readily apparent in FIG. 3 that using the engagement tool 82 to progress the set screws 76, 78 through the bores 66a, 68a will cause the set screws 76, 78 to engage the engagement surface 69. Thus, the set screws 76, 78 and their corresponding bosses 66, 68 create a clamping mechanism, which captures the receiving wall 62 between the set screws 76, 78 and the backside 67 of the mounting pad 60. Once the engagement tool 82 is removed from the door stile 34 through the tool access holes 79a, 79b the tool access holes 79a, 79b can be covered with caps, or preferably covered with remaining door structure such as the inside panel 30 with or without the perimeter framing 32, or a panic exit device 42 shown in FIG. 7 such as disclosed in Betts and Toledo U.S. Pat. No. 4,839,988. 
     FIG. 4 shows the mounting pad installed. The set screws 76, 78 are progressed, protruding outward of the bosses 66, 68 and engaging the engagement surface 69 of the door stile 34. The lock cylinder 100 is shown in end elevation view, projecting through a channel 110a formed in the lock collar 110. The lock collar 110 is an annular structure formed from the back side 67 of the mounting pad 60 and projecting through the lock hole 63 inside the door stile 34. The lock collar 110 serves to hold and guide the lock cylinder 100. The lock cylinder 100 can be a commercially available cylinder such as manufactured by Yale or Sargent. The lock cylinder 100 has a locking cam 114 which receives rotational instruction from a key (not shown) inserted into the lock cylinder 100 from exterior of the door. Turning the key causes the cam 114 to rotate about the axis of the lock cylinder 100 which in turn communicates mechanical instruction to the particular locking, mechanicals utilized interior of the door 10 or door stile 34. 
     FIG. 4 shows that the bosses 66, 68 are located above and below the lock hole 63 and straddle the vertical centerline 65 of the lock hole 63. By being so situated the set screws 76, 78 reduce a rocking play of the mounting pad 60, especially if the mounting pad was subject to a prying force such as from a screwdriver handled by a burglar, which could possibly occur if the set screws 76, 78 engaged the engagement surface 69 both along the vertical centerline. By straddling the vertical centerline, the tendency of a narrow plate to rock or pivot about its vertical axis is reduced. Additionally, by straddling the vertical centerline, the lock collar 110 and the two bosses 66, 67 can be more compactly located, permitting a shorter length of the mounting pad 60. 
     FIG. 5 shows the components which comprise the locking mechanism. The locking cylinder 100, the mounting pad 60 and a lock ring 120. The mounting pad 60 is formed of one piece including the bosses 66, 68 and the lock collar 110. The lock cylinder 100 comprises an outer flange 124 which abuts an outside portion 111 of the mounting pad 60 to halt insertion of the lock cylinder 100 through the channel 110a once the lock cylinder is fully inserted. The outside portion 111 can be a recessed annular ledge as shown dashed in FIG. 2. The locking cam 114 is also shown. 
     The lock cylinder 100 comprises a barrel portion 126 having external threads thereon. When the lock cylinder 100 is inserted into the channel 110a, some of the external threads 126a protrude inwardly of the look collar 110. The lock ring 120 can be screwed onto the barrel 126 until the lock cylinder 100 is drawn tightly to the mounting pad 60, the lock ring 120 abutting the lock collar 110 and the flange 124 abutting the outside portions of the mounting pad 60. The lock ring 120 can be of a type which is screwed on using a spanner wrench which engages indented portions 127 around the periphery of the ring 120. The lock collar 110 can be provided with keys 130 which ca engage indented portions of the barrel portion 126 (*see FIG. 4) to prevent rotation of the lock cylinder 100 with respect to the mounting pad 60, once installed. 
     Although the preferred embodiment described in the drawings illustrates a hollow stile type door, the present invention could be utilized in a solid door provided that sufficient volumes are hollowed out, such as by boring with a drill. It can be readily observed that a lock hole 63 could be bored from the receiving surface 61 of the door inwardly to communicate the lock collar 110 and locking cylinder 100 
     inwardly therethrough, and also boss holes 64a, 64b could be bored from the receiving surface 61 inwardly to receive the first and second bosses 66, 68. Tool access openings 79a, 79b could be bored laterally from the style panel surface 79 inwardly to accommodate the engagement tool 82 and also the progression travel of the set screws protruding exterior of the bosses 66, 68. The set screws 76, 78 in this embodiment would progress exterior of the bosses 66, 68 and press against an engagement surface 69 of the resulting bored out volumes. Of course, other volumes inside the solid stile would necessarily be hollowed out to receive the particular locking mechanical (not shown) which are activated by the lock cylinder 100. 
     Although other modifications and changes may be suggested by those skilled in the art, it is the intention of the inventor to embody within the patent warranted hereon all changes and modifications as reasonably and properly come within the scope of his contribution to the art.